1. Field of the Invention
The invention relates to an arrangement for applying an adhesive to the outer surfaces of an inner book to be inset into a book cover by an insetting machine, comprised of two application rollers of an adhesive application device, the application rollers positioned opposite one another within the area of adhesive application and rolling respectively along an outer surface of an inner book transported on a vertically upwardly moving saddle plate of a circulating conveyor, wherein the application rollers have a recess forming a shoulder parallel to the axis of rotation for applying the adhesive in the area of adhesive application in the groove area of the inner book, wherein the rotary position of the recess can be adjusted and changed according to the position of a certain grove shape of an inner book passing through the area of adhesive application, wherein the conveyor of the saddle plates and the rotary movement of the application rollers are connected drivingly in a cycle-synchronized manner.
2. Description of the Related Art
The adjustment of the application rollers relative to the inner book in an insetting machine up to now has required considerable time and is only possible when the insetting machine is stopped. In this context, the drive of the adhesive application rollers must be detached from the main drive in order to be able to align the shoulder of the adhesive application roller formed by the recess to the groove area or groove angle of an inner book moved on a saddle plate into the respective position.
According to German patent document DE-B-37 13 896 this disadvantage is to be eliminated in that above the adhesive application rollers a positioning indicator is arranged with which the so-called groove angle of an inner book is to be aligned at the same level, wherein this alignment position of the inner book forms the reference zero position of the conveyor to which the front edge of the recess or the shoulder of an adhesive application roller is to be adjusted. In this way, the drive of the adhesive application rollers is to be aligned by means of a positioning point analog to the shoulder of the rollers with the reference zero point of the conveyor. This may result in a better alignment and may shorten the set-up time, but the aforementioned disadvantages are not yet eliminated.
It is an object of the present invention to provide apparatus-related measures for a device of the aforementioned kind with which the alignment of the adhesive application rollers to the inner book can be significantly improved qualitatively as well as quantitatively.
In accordance with the present invention, this is achieved in that the drive connection between the conveyor and the application rollers comprises a pulling element gear unit for a continuous adjustment of the relative position between the saddle plates and the rotary position of the application rollers.
This makes it possible to perform the adjusting process between the transported inner book and the adhesive application rollers within a short period of time in an exact and very simple manner, even when the machine is running.
Decoupling from the main drive shaft is no longer required.
In an advantageous further embodiment of the inventive arrangement, the pulling element gear unit is drivingly connected by a circulating pulling element, for example, a chain or toothed belt, with the conveyor, on the one hand, and with the application rollers, on the other hand, which is a simple assembly measure that can also be realized for already existing machine concepts.
In a preferred embodiment, the circulating pulling element guided about the drive shafts of the conveyor and of the application rollers has two portions and each portion is guided about a stationarily supported roller pair of two laterally spaced apart deflection rollers and a control roller positioned between the deflection rollers and freely rotatably supported on a slide that is moveable on a guide arrangement, wherein each portion forms an open loop extending between the deflection rollers and guided about the control roller.
As an alternative, the pulling element guided about the drive shafts of the conveyor and of the application rollers can form two portions which are guided respectively about two spaced apart control rollers of a roller pair, mounted freely rotatably on a slide which is adjustable on a guide arrangement, and a stationarily supported deflection roller thus forming an open loop extending between the control rollers and guided about the deflection roller.
Both configurations of guiding the pulling element do not differ with regard to their effect, but the latter arrangement requires a slide with larger dimensions.
Moreover, it would be possible to supplement the roller pairs as in the situation of a pulley block by additional rollers so that the adjusting process of the slide could be realized with a further reducing action.
Advantageously, the slide is adjustable in the guide arrangement perpendicularly to a plane which extends through the rotational axes of a roller pair so that symmetrical conditions are present.
Expediently, for simplifying the attachment, the guide arrangement for receiving the slide is connected with the frame of the insetting machine.
The slide can be manually driven or driven by a controllable motor wherein the drive is realized mechanically or by a linear drive.
It is favorable when the slide is provided at the side facing away from the deflection rollers or the rollers, with threaded bushings into which a spindle is screwed so that a compact and easily accessible construction is realized.
For a preadjustment of the slide and for tensioning the pulling element, it is advantageous when the control rollers or the roller pairs are supported each on at least one tensioning plate that can be displaced on the slide in the movement direction of the slide.